Solar roof tile with solar and photovoltaic production of hot water and electrical energy

ABSTRACT

Object of the invention is a system composed of a special Tile, adequate to cover the whole roof, thermally insulating, ventilated, with no environmental impact, producing solar and photovoltaic energy, adequate for the production of hot water and/or electrical energy. The two functions, thermal and photovoltaic, are meant to be operated in synergy, obtaining the best result, or independently. For instance, the photovoltaic can help the thermal system, in case the covered surfaces are too small for the heating needs of the building, or in non-ideal climates, sending part of the electrical energy to electrical water heaters positioned in the boiler, to complement hot water production during low irradiation seasons. The roof thus obtained is optimal in any climate; in areas subject to snowfall the snow will melt on the tiles that anyway develop heat; in hot areas during the summer very high temperatures will be achieved, thus it will be possible to transform with heat exchangers the heat produced in cooling, obtaining air conditioning or cold water below the floor. Also, it will be possible to obtain heated water for pools from the excess of hot water both in the summer and in the winter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a National phase of International ApplicationNo. PCT/IT2007/000293 filed on Apr. 19, 2007, which claims priority fromItalian Application No. FR2006A000023 filed on Aug. 16, 2006. Each ofthese applications is hereby incorporated by reference in its entiretyinto the present application.

TECHNICAL FIELD

Object of the following patent is a “system composed of a special Tile,its variants and accessories, adequate to cover the whole roof,thermally insulating, ventilated, with no environmental impact,producing solar and photovoltaic energy, adequate for the production ofhot water and/or electrical energy”.

This system is applied in covering totally or partially roofs and walls,with modular, bi-component elements or pre-assembled ones, thermallyinsulating and ventilated, aimed at producing hot water and/orelectrical energy.

The two elements that compose a “Tile” are described in detail in thefollowing pages. They contain inside pipelines, mixing circuits,absorbing plates, and outside on the top side photovoltaic absorbers toproduce electrical energy, such as:

a—embossed metal plates, treated externally with screens and variousfilters;

b—plastic materials made of carbon polymers or similar plastics

c—embossed and/or die-cast silica derivatives

These materials, when suitably produced, with coatings and specialcolored films, look like traditional tiles in their external (superior)side.

The “Tile” with its variants and accessories is specifically suited tocover the whole roof and/or walls of a house, industrial complex or anybuilding that may be used to take advantage of solar energy, asexpressed in the main claim; has no environmental impact and can thus beused in historic centers since it can faithfully replicate shapes andcolors of traditional roof coverings, is adequate for any type ofcovering since it can be cut and shaped; has a low total cost and veryhigh energetic yield.

BACKGROUND OF THE INVENTION

Presently, electrical energy and hot water production from systemspositioned on buildings is obtained from photovoltaic and solar panelsof various types and shapes.

Traditional photovoltaic panels are made of elements of various sizes,mainly composed of silica tiles connected to form a photovoltaic cell,meant to produce electrical energy. They are protected byultraviolet-resistant glass or plastic screens, positioned above thecover or substituting the cover, for great surfaces. They absorb solarand ultraviolet rays, transforming them in electrical energy. They arenot well integrated in the architecture of the building, except inextremely modern buildings where whole sections of the roof oradequately exposed walls are used.

Solar panels instead, used to collect solar radiant energy to producehot water, are made of a solar collector which is simply a plate thatcollects solar radiation. A circuit is connected to the plate. Thecircuit allows the circulation of a fluid meant to remove thermal energyfrom the plate and to bring it to the internal network in order to beused. The inner components of the system are protected by an externaltransparent screen, like the one of photovoltaic panels, and by athermally insulating screen positioned below, meant to avoid heatdispersion.

Solar panels have the same problems of photovoltaic panels; since theyare positioned above the roof cover, or substituting it in the case oflarge surfaces, they do not integrate at all in the architecture of thebuilding, thus creating a significant environmental contrast with thesurrounding environment. Installation of these elements on roof coversis quite complex and often causes rain water leakage in time, bothsystems are too expensive in relation to the real energetic yield theyproduce. Several years are needed to counterbalance the installationcost; this factor significantly limits their use even today.

In the last years several inventors have dedicated themselves to findingalternative solutions to traditional solar and photovoltaic panels.Several patent applications have been requested and granted, both inItaly and abroad, for various types of products (covering tiles, tiles,etc.) with the objective of optimizing either the production of hotwater, or of electricity, independently, with absorbing elements meantto cover buildings totally or partially, substituting solar andphotovoltaic panels on the market today. These approaches forgot toconsider that, in order to achieve a valid result, the “coverage system”needed to be improved mostly, using a system that could substitute thecommonly used tiles, easily adjustable to any situation, avoidingenvironmental impact problems, able to produce hot water and electricenergy through solar rays collection.

These new proposed or patented systems have not achieved any significantresult, since they have not been accepted and produced by the industry,which still today produces traditional solar and photovoltaic panels.They also do not satisfy practical and functional requirements, inrelation to adjustability to various roofs, cost lowering, performanceand most of all compatibility with traditional roof coverings; in ordernot to create any environmental impact and be able to use them intraditional architecture and historic centers.

SUMMARY OF THE INVENTION

Currently, optimal and well implemented coverage of a house or more ingeneral, of a building, is achieved through positioning thermallyinsulated and ventilated panels, positioned horizontally on the inclinedtop of an attic or traditional wooden top, on top of which terracottaroofing tiles, cement, slate, canadian tiles, other types of tiles, etc.are positioned. These coverings are made perfectly compatible with thesurrounding environment by choosing the right type of tile depending onthe location and thus satisfy the aesthetic and waterproofingrequirements. They do not use, but simply dissipate the solar energythat they accumulate.

The new covering system proposed uses specifically-made Tiles to coverthe entire building, becoming part of it, producing at the same time hotwater for house use, for heating, and electrical energy, throughcollection and absorption of solar and ultraviolet radiation.

The new patent fully addresses the following requirements:

1. Insulates thermally the house's roof, providing optimal temperature.The problem of overheating of the highest floors caused by lack ofadequate insulation and ventilation is common also with traditionalsystems

2. Creates an adequate ventilation between the insulating material andthe roof structure below, both for wooden roofs, as in anglosaxonbuildings of northern Europe, north America etc., or in reinforcedconcrete, as in traditional Italian buildings

3. Perfectly suits the architectural project, since the external surfacereproduces the same shapes and colors of the various traditional tiles,thus allowing to use the new coverings also in historic centers andreligious buildings.

4. May be used both on pitched roofs or on walls facing north, wherethere is no adequate solar irradiation, and on well-irradiated wallsfacing south, south west and south east

5. May be easily shaped, since not all roofs are linear and rectangular,to match corners, dormer windows, differences in roof height, etc. To beadjusted to this type of situation, it can be cut with a hacksaw andshaped depending on the technical needs, without wastes of time6. It is a covering element with optimal, non-bulky size, adequate tomeet technical and positioning requirements described previously. Itsatisfies insulation and plain covering requirements for walls facingnorth, while for irradiated parts it is a solar energy absorber, inorder to produce both hot water and electrical energy, also separately,depending on needs. It resists weathering in time, it is easy to attachto the lower structure with a plug or nail, it is easy to be substitutedor renewed on the external walk-on surface, exposed to weathering, everyelement is attached to the next vertically, thanks to male/female metalor plastic joints with adequate gaskets, while sideways they areoverlapping.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1—Cross section of a type “A” “Tile” to produce thermal and/orelectrical energy, with construction details, appearing externally as atraditional, portuguese type tile, of which the top tile, the base, thebifocal lens and the internal “boiler” with plate and absorbing pipesare evident.

FIG. 2—Axionometry view of a type “A” “Tile” to produce thermal and/orelectrical energy, with two covering tiles and the base normallypositioned. The top tile has bifocal lenses. It is positioned backwards(not in the closed position) in order to show the inside of the tilewith the plate, the absorbing pipes and the lower thermally insulatingfoam.

FIG. 3—Axionometry view towards the lower part of a type “A” tile toproduce thermal and/or electrical energy, with two covering tiles,lenses type Fresnel, male joints, positioning braces and air chamber.

FIG. 4—Axionometry view of a type “B” “Simple tile” with two coveringtiles, without bifocal lenses, with thermally insulating foam,positioning braces, air chamber, upper fixing points, base, and positionof the first tile on the gutter pipe.

FIG. 5—Cross section of a type “B” “Simple tile” appearing externally asa traditional portuguese type tile, with top tile, base, insulatingfoam, fixing braces, positioning braces, air chamber

FIG. 6—Cross section of a male/female joint connected to the pipes,which allows the perfect and simple fixing of a lower and an upper tile.

FIG. 7—Cross section of a type “A” “Tile” for the production of thermaland electrical energy with construction details, appearing outside as atraditional portuguese type tile. The upper tile is evident, togetherwith the base, the lens, the inner “boiler” with plate and absorbingpipes and most of all the silica plates to increase electrical energyproduction, positioned on the lower flat part of the tile.

DETAILED DESCRIPTION

An innovative coverage system, meant not only to cover buildings, butalso to produce thermal and photovoltaic energy, to be introduced in theinternational market as a substitute for the existing products used tocover roofs and walls, has to satisfy simultaneously the followingrequirements:

The elements used have to cover the whole surface of the roof and, ifapplicable, also well-exposed walls, they have to suit well thearchitectural design, they have to be adequate to thermally insulate theroof, they have to suit the environment, they have to use the irradiatedsurfaces optimally and continuously, turning the covering into a singleheat absorbing element for the production of hot water (eliminating theboiler) and for the production of electrical photovoltaic energy,significantly lowering the energetic expense for the building. If thecovering is installed in the building phase, the cost lowering ismaximal. A fundamental issue which should be considered is that only apart of the roof cover is positioned facing south, southwest orsoutheast, and can be optimally used to absorb solar energy, while allthe remaining surface facing north can be used only for a partialabsorption of ultraviolet rays.

The invention described in this patent introduces improvements andradical changes in the implementation of roof coverings of houses andbuildings which can be summarized as follows:

System suited to any type of building, both italian and anglosaxon, withreinforced cement or wooden roofs, total modularity, low cost withrespect to the total energetic yield, ease of transport and ofinstallation, zero aesthetic and environmental impact, lowering ofelectrical and thermal energy production cost with respect toalternative systems to the ones used, lowering of the photovoltaic costin relation to the huge surface used, with financial aids from thegovernment, in relation to the initial investment or other incentivesactive in other countries. The fundamental idea in the main claim ofthis patent is to obtain all the functions of a perfectly insulated andventilated roof cover, together with the energetic yield coming from thetotal roof surface or a large part of it, aimed at exploitingsimultaneously or separately photovoltaic and thermal solar energy.

The system uses a single element, a newly designed “Tile”, whose sizeand shape can vary depending on needs, which can be produced both as asingle, pre-assembled element, and in two separate parts, the topdefined “covering tile” and the bottom defined “base”, to be assembledduring installation. The “Tile”, of varying size depending on the modelsand types it replicates, exists in two types, “A”, and “B”, which areidentical externally in both components, but differ in the insidecontents.

Type “A” (FIG. 1-2-3) is used in the adequately irradiated rooffractions, producing:

a—thermal energy through solar irradiation (FIG. 1 n. 3) of the insideof the Tile, collected optimally from the custom-built top side andenhanced through the use lens type Fresnel to concentrate the rayssolariums to the inside (FIG. 1 n. 1) positioned in the convex part(FIG. 1 n. 13) of the same tile, in order to capture sun rays from anyangle, distribute and enhance them (FIG. 1 n. 3) inside the cavity ofthe tile (FIG. 1 n. 18), irradiating the metal plate and/or theradiation collecting pipes (FIG. 1 n. 2-4)

The use of the lens type Fresnel is optimal with metallic Tile, when thesun slant or the general situation is not satisfactory, it allows toposition the tiles with any tilting and thus to apply them directly onany surface, disregarding the sunlight slant as with solar panels. Whenthe sun rays hit the concave, collecting metal plate (FIGS. 1 and 2)inside the cavity, a series of reflections enhance the irradiatingeffect. Just like in a pool table, the rays bounce (FIG. 1 n. 3) and hitall internal surfaces (FIG. 1 n. 14) and their absorbing pipes (FIG. 1n. 4), including the main one (FIG. 1 n. 15) positioned at the center ofthe convex part of the top tile. The inner surface of the top tile (FIG.1 n. 13) is specifically treated in the case of tiles where plasticmaterials are used which are transparent on the external side and opaqueand reflecting on the inside, so that solar and ultraviolet radiation isallowed in but not out, creating a greenhouse effect which increases theheat provided to the collector. The collecting plate (FIG. 1 n. 2) ispositioned on insulating foam (FIG. 1 n. 16), with concave shape inside,inserted in the base element (FIG. 1 n. 6), the collecting pipes(FIG. 1. n. 4) are positioned on the plate (FIG. 1 n. 2), their numberis suited to the specific use. For specific applications a double layer,embossed absorbing plate, with adequate canals acting as pipes; can beproduced. All pipes inside every tile (FIG. 6 n. 21-24) are connectedwith the corresponding ones of the previous and subsequent one throughmale/female joints (FIG. 6 n. 23) with adequate sealing gaskets (FIG. 5n. 7), in plastic or metal, suited to create a single circuit thatconnects all the tiles together to a heat exchanger for the productionof hot water; the joining system allows a quick connection between thetiles without time consuming screwing, welding, etc.

b—electrical energy from photovoltaic energy through sun and ultravioletrays absorption on behalf of the top of the tile (FIG. 1 n. 13-14).These tile elements (FIG. 1-2-3), connected to each other with specificjoints (FIG. 1 n. 8) in plastic or metal as described later, turn theentire roof cover into a single photovoltaic panel.

Type “B”, defined “simple tile”, is meant as a jolly (FIG. 4),adjustable to any roof shape, to be used in those parts facing norththat do not produce thermal energy and/or in difficult spots, where itis not necessary to use the energy producing tile. This element iscomposed of the “top tile” (FIGS. 4-5 n. 13-14-5) without lens typeFresnel, and of the same lower “base” (FIGS. 4-5 n. 6), eitherpre-assembled, or assembled later, foamed inside (FIGS. 4-5 n. 16), andforming a single tile which can be cut, shaped etc., adjusting it to anycovering need.

The “base” is made of a thermic hardened plastic or metal, forming asort of a box without a lid, where the lid is the top tile. The base hascontaining side walls a few centimeters high (FIGS. 1-2-3-4-5 n. 6),inside which the thermally insulating, type polyurethane orpolystyrene-like material is foamed (FIGS. 1-2-3-4-5 n. 16). The foamtakes the specific concave shape on the top, onto which the absorbinglayer is positioned. In the case of the simple tile, the foam fills thewhole cavity, increasing the protection and thermal insulation of theless irradiated parts (FIG. 4 n. 16). The base forms an adequate air andventilation chamber (FIGS. 1-3-5 n. 5) between the lower stand and thetile, being raised from the stand a few centimeters through guides orpositioning stands (FIGS. 1-3-4-5 n. 10-12) also used to attach the tileunit with plugs or nails (FIGS. 1-3-4-5 n. 11) to the lower structure(FIGS. 1-3-4-5 n. 17), to avoid damage of the cover due to strong winds.For special needs, the base support can be made in rigid polyurethane orsimilar products, without using the external structure of the basesupport. It includes the space and adequate shape to fit in theabsorbing plate, if appropriate with pipes contained in the polyurethaneand guides and supports being part of the same unit.

The air chamber and the foaming avoid energy dispersion and condensationoutside. The absorbing, concave galvanized metal, reflecting plate lieson the thermally insulating foaming. On top of it, some absorbing pipesare positioned, inside which runs a cheap liquid of high calorificvalue, like nitrogen mixtures and liquid phosphorus.

An additional central absorbing pipe (FIGS. 1-3-5—n. 15) is positionedat the center of the concave cavity of the base, and of the convexcavity of the “upper tile”. It lies on specific lodgings positioned atthe two ends of the base (FIGS. 1-5 n. 8). All the pipes of the thermalsupport have at the vertical ends of the base male/female joints (FIGS.1-6 n. 19-20) to connect to the adjacent tile. The base also has sideguides (FIGS. 1-5 n. 9) to match the fixing points from the upper tile(FIGS. 1-5 n. 8).

The “covering tile” is made in any transparent plastic material or incarbon polymers coated with silicon films or conducting electrodes withmicro/nano structural organic paint (one or more layers), adequatelyprotected and resistant to ultraviolet rays, of an adequate color tomatch the color that the top tile will have according to architecturalneeds. If it is made with a heat conducting and absorbing metal layer(copper, alumina, etc.), it will be “doped” by coating it with suspendedfilms of amorphous silica (double or triple joint) in the desired color,made porous through electrolytic attack, in order to exploit a widerband of the solar spectrum, or with other layered films suggested by thelatest technical achievements, like silica films or other, adequate tocollect photovoltaic energy from solar and ultraviolet rays. In thiscase too, the color of the external stand (FIGS. 1-3-5 n. 13) will bewhat is suggested by the architectural needs. This top tile, thickenough to be able to be walked on, depending on size and material, ismade with the external shape of the traditional tile one wants toreproduce, or with a novel design, and has joints to allow overlaps,shaping, etc. It has adequate gaskets (FIGS. 1-5 n. 7) to make iswater-tight, avoid condensation and leaks of vapour produced inside. Italso has specific threaded plugs on the sides (FIGS. 1-5 n. 8) to attachit by pushing it into the side guides of the lower support (FIGS. 1-5 n.9), making it a single and continuous unit with the other tiles.

The top tile hosts in its top, central convex part, as shown previously,a lens (FIGS. 1-2-3 n. 1) which allows to attract sun rays (FIGS. 1-5 n.3) from any angle, distributing and enhancing them inside the tile.These rays are reflected by the Fresnel lens inside the oval cavitybetween the two parts of the tile, at the center of which runs the mainpipe of the absorbing liquid. Solar rays enter the cavity, which is areal boiler, are reflected on the mirror metal plate below on the main(FIGS. 1-5 n. 15) and side (FIGS. 1-2-3 n. 4) pipes, heating the liquidto high caloric temperatures. The inner concave side of the top tile istreated in order to make it opaque and reflecting on the inside. Forpolycarbonates or another plastic and vitreous materials, reflectingpaints will be used not to allow rays to escape; for metal supports,they will be galvanized inside so that they reflect the rays inside thecavity.

A variant of “A” type tile is shown in FIG. 7. It is made of a slightlymore expensive system, adequate to increase electrical energyproduction, with the help of silica crystals positioned on specificlodgings on top of the absorbing plate (FIG. 7 n. 26), protected by thetop tile. This type may be used in “Tiles” that use the top tile made oftransparent glass support or plastic polycarbonate, etc., or with metaltop plates (FIG. 7 n. 13-14), assembled together with vitreous orplastic parts (FIG. 7 n. 25) positioned matching the lodging of thesilica crystals. These are all connected together through specificconnections below the top tile, to form a single photovoltaic panel.

Components Description and Installation System

Installation of the “A” type tiles which produce thermal and electricalenergy: After having levelled the surface, first a horizontal line ofbase supports should be positioned, from left to right as fortraditional tiles, screwing on the lower structure the guides of somesupports, depending on weather requirements, cutting the last tile onthe right sideways with a hacksaw or similar tools, using a simple basetile until the metal structure on the side is reached. After positioningcorrectly and with the right vertical tilt the first row of basesupports, the supports of the second adjacent line are positioned, oneby one, fixing vertically the central and lateral pipes on the lower andupper tiles through the specific male/female joints, simply lifting theback support and pushing down until a “click” is heard. After the secondline of base supports is attached, the first row of covering tiles ispositioned, overlapping them one to the next from left to right andvertically aligning them to the lower tiles. After the top tiles areinstalled, the completed part of the roof can be safely walked on,continuing to install one line of base supports and one line of coveringtiles until the end. In case the last tile is too long, the base supportwill be cut, in this case the one with pipes that will be subsequentlyconnected with normal hydraulic joints. The pipes in the last basesupport and the complete or cut covering tile will be connected withinsulated distribution copper pipes positioned inside of the base, theywill be foamed and insulated after installation, covered with the samematerial used for the top tiles, and brought to and connected to theinsulated boiler heating coils in order to produce hot water. The boilershould possibly be positioned close to the roof or in a specific placewhere it is to be connected to the heating system of the building. Inthe specific case of using the system in an area with intense sunexposure, the system may even produce steam.

As far as the production of electrical energy meant to be sent to anaccumulator or to Hydro lines on the basis of the government aids, itshould be specified that the four connection bolts to the lower baseallow to connect all the top tiles facing north or irradiated sides, inorder to obtain a single photovoltaic surface for the whole roof, sincethey are connected to the lower structure. In addition, they can createan even wider surface, connecting through bolts to plates or tilespositioned vertically or to other photovoltaic energy producing tiles.

The tiles that are applied to the walls of the buildings may be used toproduce thermal and photovoltaic energy, using a normal tile, or justphotovoltaic energy using a simple tile with or without internalinsulation. The external surface of the top tile in this case takes theshape, size and color adequate to the architectural needs of the whole.

Installation of the Tiles that Only Absorb Ultraviolet Rays, Positionedon Pitched Roofs or on Walls Facing North, or where Thermal Connectionsare not Practical:

After the installation of type “A” tiles is complete in optimallyirradiated positions, installation proceeds along the same lines for thesimple type “B” tiles, which are only insulated, until roof covering iscomplete, or vertical walls which are able to use ultraviolet radiationin the absence of direct irradiation. Both the upper and the base tilesare cut, shaped and adjusted to the shape they are meant to cover.

Special Components and Possible Other Applications of the System:

In the production phase, the upper tiles, made in plastic or in metal,may contain on the inside metal wirings to allow connection of the roofto other specific panels, containing wirings connected to dispersingpoints, aimed at obtaining a Faraday cage for the whole building, orother.

To complete the system, special parts not shown in the picture are used.These are plastic or metal side bands, to cover the lateral cuts oftiles, the joints to the thermal and electrical distribution system, thejoints with the silica crystals and the borders of the roof.

1. A covering tile for roof and wall structures of buildings,comprising: an upper element comprising a convex portion having an innersurface treated so as to be reflecting, the upper element being coatedwith one or more first photovoltaic elements, a base, provided with areflecting plate covering a thermally insulating element, having aconcave portion in correspondence with the convex portion of the upperelement, said convex portion of the upper element and said concaveportion of the reflecting plate forming a cavity wherein a greenhouseeffect is produced when the tile is exposed to solar radiation, aradiation absorbing main pipe being positioned within the cavity incorrespondence with a center of the convex portion of the upper element,the base being provided with lower positioning stands, so as to becapable to be supported by the stands over a structure and to form anair and ventilation chamber, wherein the reflecting plate comprises aflat portion outside the cavity, wherein one or more second photovoltaicelements are positioned in corresponding housing, and wherein acorresponding portion of the upper element is made of transparent glassor plastic polycarbonate or plastic.
 2. A covering tile according toclaim 1, comprising one or more radiation absorbing lower pipespositioned in contact with the reflecting plate.
 3. A covering tileaccording to claim 2, wherein said lower pipes are made by means of thereflecting plate and a second lower plate which define channels actingas said lower pipes, whereby said lower pipes are incorporated in adouble layer plate formed by the reflecting plate and the second lowerplate.
 4. A covering tile according to claim 2, wherein said lower pipesare provided with end male, or female joints and sealing gaskets.
 5. Acovering tile according to claim 1, wherein the upper element isprovided with either a bifocal or Fresnel lens for concentrating solarradiation within the cavity.
 6. A covering tile according to claim 1,wherein the main pipe is provided with end male or end female joints andsealing gaskets.
 7. A covering tile according to claim 1, wherein theupper element is internally provided with metal wires.
 8. A coveringtile according to claim 1, wherein the upper element is made of metallicmaterial, or plastic material or carbon polymer material or vitreousmaterial.
 9. A covering tile according to claim 1, wherein said coveringtile is made of a transparent plastic material or of carbon polymerscoated with silicon films or conducting electrodes with one or morelayers of micro/nano structural organic paint or suspended films ofamorphous silica.
 10. A covering tile according to claim 1, wherein thethermally insulating element is inserted in or is integral with thebase.
 11. A covering tile according to claim 10, wherein the thermallyinsulating element is foamed.
 12. A covering tile according to claim 11,wherein the thermally insulating element is made of rigid thermohardenedpolyurethane or polystyrene.
 13. A covering tile according to claim 1,wherein the upper element and the base are connected to each otherthrough either plastic or metal joints.
 14. A covering tile according toclaim 13, wherein said plastic or metal joints comprise side threadedplugs or fixing pins of the upper element insertable in correspondingside guides of the base.
 15. A covering tile according to claim 1,wherein the upper element is made of a metallic material, wherein theinner surface is galvanized.
 16. A covering tile according to claim 1,wherein the inner surface of the upper element is coated with areflecting paint, so that the upper element is transparent on anexternal side and opaque on the inner surface.
 17. A covering tileaccording to claim 1, wherein said one or more first photovoltaicelements comprise suspended films of amorphous silicon made porousthrough electrolytic attack.
 18. A system for covering roof and wallstructures of buildings and producing thermal and photovoltaic energy,comprising a first plurality of covering tiles, wherein each coveringtile comprises: an upper element comprising a convex portion having aninner surface treated so as to be reflecting, the upper element beingcoated with one or more first photovoltaic elements, a base, providedwith a reflecting plate covering a thermally insulating element, havinga concave portion in correspondence with the convex portion of the upperelement, said convex portion of the upper element and said concaveportion of the reflecting plate forming a cavity wherein a greenhouseeffect is produced when the tile is exposed to solar radiation, aradiation absorbing main pipe being positioned within the cavity incorrespondence with a center of the convex portion of the upper element,the base being provided with lower positioning stands, so as to becapable to be supported by the stands over a structure and to form anair and ventilation chamber, wherein corresponding pipes of adjacenttiles are connected to each other and to a heat exchanger or insulatedboiler heating coils for the production of hot water, or steam, whereinthe photovoltaic elements of the tiles are connected together and to anaccumulator or electrical distribution system, wherein the tiles aresupported by the respective lower positioning stands over a structure soas to form the air and ventilation chamber wherein the reflecting platecomprises a flat portion outside the cavity wherein one or more secondphotovoltaic elements are positioned in corresponding housing, andwherein a corresponding portion of the upper element is made oftransparent glass or plastic polycarbonate or plastic.
 19. A systemaccording to claim 18, wherein a fluid having high calorific value flowsinto the pipes of the plurality of covering tiles.
 20. A systemaccording to claim 19, wherein said fluid is a mixture of nitrogen andliquid phosphorus.
 21. A system according to claim 18, which furthercomprises one or more second covering tiles comprising an upper element,having a convex portion, and a base, provided with a thermallyinsulating element, wherein the upper element is coupled to the base soas to lie on the thermally insulating element.
 22. A system according toclaim 21, wherein the thermally insulating element is foamed.
 23. Asystem according to claim 22, wherein the thermally insulating elementis made of rigid thermohardened polyurethane or polystyrene.
 24. Asystem according to claim 21, wherein the upper element is coated withone or more photovoltaic elements connected to the photovoltaic elementsof the first plurality of covering tiles.
 25. A system according toclaim 18, wherein at least a subset of the covering tiles which thesystem comprises overlap each other.
 26. A system according to claim 18,wherein each covering tile comprises one or more radiation absorbinglower pipes positioned in contact with the reflecting plate.